THE SENSITIVE LAMIX.-E. .71 



second (laminal) constituent of the bars. AVe, therefore, see 

 that the bars are compound in origin, and may theoretically be 

 divided into a " coronary " and a " laminal " portion. 



Although, when the hoof is removed, the isolated sensitive 

 laminae appear to lie closely packed together, they are really 

 divided by deep furrows, wdiich, in life, accommodate the horny 

 laminae of the wall. The sensitive laminae may be compared 

 to the leaves of a book, — that is, they are fastened by their 

 posterior margin to the corium covering the pedal bone and 

 vessels, whilst their anterior margin and lateral surfaces are 

 free. The isolated laminae are very narrow above, just below 

 the coronary band, and become broader as they descend, 

 attaining their greatest breadth at the centre, which breadth 

 they preserve as far as the ground, decreasing, however, in 

 thickness, so that at the base they are markedly thinner. They 

 terminate in papillae resembling those of the sensitive sole. 

 The " toe " of the foot presents the broadest and most numerous 

 lamina?. Towards the sides and quarters they become narrower 

 and more widely spaced. In the bars they are most slender 

 and widest apart. In a similar way the lamina of the 

 toe are the longest ; those of the quarters become shorter 

 and shorter, until they gradually cease. Their breadth varies 

 from 2*5 to ^ of an inch, their length from '^\ at the bars 

 to 2 or 3 inches at the toe, depending on the size of the foot. 

 The number of laminae is not always the same. As a rule, 

 there are about 25 to a centimetre at the toe,* 21 to 22 at the 

 quarters, 15 to 17 at the heels, and at the bars only about 10, 

 so that the entire number may be estimated as between 550 

 and 600, depending on the size of the foot. 



To the naked eye the lamina^ appear quite Hat, but under 

 the microscope they are seen to present a number of small 

 projections w^hich have been called secondary laminae, running 

 more or less in the same direction as the laminae ; in fact, each 

 lamina reproduces the same structure in miniature as the entire 

 sensitive wall. The sensitive laminte produce the laminal 

 portion of the wall, and serve especially to connect the corium 

 and the horny wall. The strength of this elastic connection ia 

 greatly increased by the enormous surface presented by the 

 secondary laminae (compare with fig. 50). 



* Two and a half centimetres eqnal nearly one inch. 



